Tandem SN2-Michael reactions for the preparation of simple five- and six-membered-ring nitrogen and sulfur heterocycles
摘要:
A one-pot tandem S(N)2-Michael addition sequence has been developed for the preparation of five-membered- and six-membered-ring nitrogen and sulfur heterocycles from 6- or 7-halo-2-alkenoate esters. Nitrogen-containing rings are prepared by reaction of the omega-halo-2-alkenoate ester with a primary amine in the presence of triethylamine. The sulfur analogues are generated by thiourea displacement of the halide followed by base hydrolysis of the isothiouronium salt. Yields are routinely in the 60-80% range. Experiments are described which elucidate the chronology of the reaction sequences. Ring size and steric hindrance to the initial substitution reaction appear to be the only limitations of the procedure.
Beta-Amino-Acid derivatives as inhibitors of matrix metalloproteases and TNF-Alpha
申请人:——
公开号:US20020013341A1
公开(公告)日:2002-01-31
The present application describes novel &bgr;-amino acid derivatives of formula I:
1
or pharmaceutically acceptable salt or prodrug forms thereof, wherein A, X, Z, U
a
, X
a
, Y
a
, Z
a
, R
1
, R
2
, R
3
, R
4
, and R
4a
are defined in the present specification, which are useful as metalloprotease and/or as TNF-&agr; inhibitors.
本申请描述了式I的新型β-氨基酸衍生物:
1
或其药用可接受的盐或前药形式,其中A、X、Z、U
a
、X
a
、Y
a
、Z
a
、R
1
、R
2
、R
3
、R
4
和R
4a
在本规范中有定义,这些衍生物可用作金属蛋白酶和/或TNF-α抑制剂。
BF<sub>3</sub>·Et<sub>2</sub>O as a metal-free catalyst for direct reductive amination of aldehydes with amines using formic acid as a reductant
作者:Zhenli Luo、Yixiao Pan、Zhen Yao、Ji Yang、Xin Zhang、Xintong Liu、Lijin Xu、Qing-Hua Fan
DOI:10.1039/d1gc01468d
日期:——
direct reductive amination of aldehydes with amines using formic acid as a reductant under the catalysis of inexpensive BF3·Et2O has been developed. A wide range of primary and secondary amines and diversely substitutedaldehydes are compatible with this transformation, allowing facile access to various secondary and tertiary amines in high yields with wide functional group tolerance. Moreover, the